System and method of digital rights management

Abstract

A method and a system of digital right management on a computer system. Protected video content is decrypted where encoded frames of data are buffered and overwritten after decoding to prevent the unauthorized copying. The system includes a software client that has a user identifiable key for tracing any unauthorized copying of the client and decrypted video file.

What is claimed is: 
     
         1 . A method of video content digital rights management on a computer comprising the steps;
 decrypting a first encoded frame of video from an encrypted digital video source into a memory buffer;   providing the memory buffer to a video decoder;   decoding the first encoded frame thereby forming a first frame;   decrypting a second encoded frame of video content into the memory buffer upon receiving an indication that the first encoded frame is decoded.   
     
     
         2 . The method of  claim 1  wherein the encrypted video content is encrypted with a public-key cryptography. 
     
     
         3 . The method of  claim 2  wherein the encrypted video source is comprised I-frames, P-frames and B-frames. 
     
     
         4 . The method of  claim 3  wherein the indication that the first encoded frame is decoded occurs either when the memory buffer is copied or the decoder generates the indication. 
     
     
         5 . The method of  claim 4  wherein the video source is encoded according to MPEG-2, MEPG-4, MPEG-4 AVC, H.264, or AVI standards. 
     
     
         6 . A method of video content digital rights management on a computer comprising the steps;
 decrypting one or more encoded frames from an encrypted encoded video source into a memory buffer;   decoding from the memory buffer each of the one or more encoded frames;   altering one or more of the encoded frame after decoding, wherein the altering would prevent the subsequent decoding of the frame.   
     
     
         7 . The method of  claim 6 , wherein the decrypting the one or more encoded frames begins with an encoded full video frame. 
     
     
         8 . The method of  claim 7 , wherein the encoded full video frame is an encoded I-frame. 
     
     
         9 . The method of  claim 7 , wherein the altering of the one or more encoded frames is performed by decrypting a new encoded frame into the buffer and thereby overwriting part of the buffer with new video content. 
     
     
         10 . The method of  claim 8  wherein the altering of the one or more encoded frames is performed by changing data within the full encoded frame. 
     
     
         11 . The method of  claim 6  wherein decoding of the frame generates and an indication of the generating a decoded frame and wherein the alteration of the one or more frames occurs subsequent to the indication and the B-frame data is overwritten. 
     
     
         12 . The method of  claim 9  wherein the decryption is based on public-key encryption. 
     
     
         13 . A system for digital rights management comprising:
 a computer configured with a client having a unique computer associated decryption key;   a computer accessible media source configured with an encrypted encoded video file;   a memory buffer; and   a video decoder, wherein the client is configure to decrypt one encoded frame at a time into the memory buffer, transfer the data to the video decoder, and alter the encoded frame data after transfer to the video decoder.   
     
     
         14 . The system of  claim 13  wherein the client is configured to decrypt and overwrite the buffer with a second encoded frame after the one encoded frame in the buffer is transferred to the video decoder. 
     
     
         15 . The system of  claim 13  wherein the encoded frame is an I-frame, P-frame, or B-frame. 
     
     
         16 . The system of  claim 15  wherein the client is configured to alter only the encoded I-frame and wherein the client is configure to modify the encoded I-frame such that it cannot be decoded. 
     
     
         17 . A system for digital rights management comprising:
 a computer configured with a client having a unique computer associated decryption key;   a computer accessible media source configured with an encrypted encoded video file;   a memory buffer; and   a video decoder, wherein the client is configure to decrypt one or more encoded frames into the memory buffer, wherein the decoder is configured to decode the one or more encoded frame and configured to alter one or more of the one or more encoded frames after decoding one or more of the one or more encoded frames.   
     
     
         18 . The system of  claim 17 , wherein the client is configured to have the first frame in the memory buffer to be an encoded I-frame. 
     
     
         19 . The system of  claim 18 , wherein the altering the one or more of the one or more encoded frames is by the client being configured to load a new encoded I-frame into the memory buffer. 
     
     
         20 . The system of  claim 18 , wherein the wherein the altering modifies the first encoded frame in the memory buffer such that the first encoded frame cannot be decoded. 
     
     
         21 . The system of  claim 20 , wherein the encrypted video source uses public key encryption.